Latest commercial supply ship set for destruction

Sen—Astronauts on the International Space Station will today cast adrift the Cygnus spacecraft that was the latest commercial vessel to bring them supplies from home, sending it to a fiery demise in the atmosphere.

The Orbital Sciences ship had spent more than a month attached to the space station’s Harmony mode after arriving on 12 January laden with 1,261 kg (2,780 lb) of cargo. It included vital science experiments, crew provisions, spare parts and other hardware.

Expedition 38 Flight Engineer Michael Hopkins of NASA and Koichi Wakata of the Japan Aerospace Exploration Agency will use the ISS’s robotic arm Canadarm2 to detach and release Cygnus. They will operate from the station’s seven-windowed cupola “conservatory”, giving them a clear view of events.

Hopkins and Wakata teamed up last week to train for the robotics work needed to grapple and release Cygnus. Hopkins had previously grappled the spacecraft on its arrival in January, and Wakata and NASA’s Rick Mastracchio then brought it in for berthing.

As is customary when dispatching doomed unmanned craft, Cygnus has been filled with the space station’s trash. It is due to be unfastened from Harmony’s Earth-facing port at about 10.30 UT (5.30 a.m. EST) and will be released at 11.40 UT (6:40 a.m EST).

Cygnus will fire its engines twice, sending it out of orbit for a destructive re-entry into Earth’s atmosphere, and it will burn up over the Pacific Ocean. The deorbit sequence will begin shortly after 13.00 UT (8 a.m. EST).

The mission, Orb-1, has seen the second Cygnus fly to the ISS as part of NASA’s Commercial Orbital Transportation Services programme (COTS). Orbital has a $1.9 billion Commercial Resupply Services (CRS) contract with NASA and a total of eight missions are due to deliver around 20,000 kg of cargo to the ISS before the end of 2016.

A set of CubeSats are released from the NanoRacks deployer on the end of the Kibo laboratory robotic arm. Credit: NASA

In other activities aboard the ISS in the past week, a pair of CubeSats were deployed from the Kibo laboratory’s robotic arm, the latest in a number of planned releases of the mini satellites that arrived aboard Cygnus.

They were released on Thursday by the NanoRacks Launcher attached to the end of the Japanese robotic arm. This is a commercial device designed by NanoRacks, a company that provides research facilities on the orbiting outpost to business and public organisations.

The previous day, the device had failed to deploy a set of CubeSats, causing Japanese and U.S. controllers to review the status of further deployments.

The next commercial mission to the ISS is due to be another cargo resupply flight by Space Exploration Technologies (SpaceX), which will launch its Dragon spacecraft on a Falcon 9 rocket on Sunday, 16 March, from Cape Canaveral Air Force Station, Florida.

It will be the company’s third commercial resupply mission to the space station, and will deliver several tons of supplies, including new science experiments and technology research material.